How do I get this odd geometric hole in smooth surface right?
There are any number of correct solutions depending on your needs. I propose this one, because it keeps the element in a four sided square that can be edited quickly and incorporated into the rest of the mesh without difficulty:



And I would advise using a bevel modifier rather than a subsurf modifier in this situation. It gives those nice rounded edges while leaving you free to to structure your topology for ease of use, and you can use Ngons if you like. I like to use the "Angle" limiting method to only bevel sharp corners. But you can be as specific as you like using bevel weights.



If you must use a subsurf modifier, I recommend using the "Edge Crease" tool (SHIFT + E) where possible instead of adding loop cuts to sharpen corners. It makes the mesh shape far easier to edit.